The ability to sense or measure a physical quantity or chemical substance has been a desirable research endeavor for decades. Increasingly, there exists a need for rapid, accurate, reproducible, and economical sensors. Of particular interest to many are sensors capable of detecting biologically relevant analytes. A method for the accurate detection, quantification, and discrimination of biological molecules would be of great benefit to many technical fields including biochemistry, food science, and medicine.
Technology capable of sensing biologically relevant analytes exists. Noteworthy are electronic nose and tongue technologies that are finding increasing utility in the food science industry. While these technologies and technologies alike are able to identify different classes of analytes, their ability to discriminate between analytes of the same class is limited. One class of analytes that can often be difficult to detect and discriminate between as well as from among other analytes is biogenic amines. Biogenic amines have been associated with a variety of problems in the food science and medical industries. An increased production of biogenic amine by an organism, for example, can result from rapid cell proliferation. Consequently, biogenic amine levels can serve as indicators of health complications, including cancer, bacterial infection, and food poisoning, to name a few. If a human, for example, is exposed to elevated biogenic amine levels present in food, this exposure can trigger a wide range of symptoms ranging from headaches to life-threatening episodes of blood pressure spikes.
Biogenic amines can also serve as indicators of food spoilage caused by bacteria (i.e. to indirectly detect the presence of bacteria). Food spoilage (e.g., meat and fish spoilage) occurs as bacteria begin to grow shortly after the time of slaughter. During the initial stages of food spoilage, free amino acids are decarboxylated by enzymes released by invading spoilage microorganisms. The product of decarboxylation includes biogenic amines, namely putrescine and cadaverine. These two amines are particularly distinctive in odor and correlate well with surface bacterial counts. Another product, histamine, is of interest due to its alleged ability to induce histamine intoxication, a form of food poisoning associated with the consumption of spoiled fish.
Several methods exist for detecting biogenic amines. Classical methods for detecting biogenic amines include chromatographic techniques, such as gas chromatography, thin layer chromatography, reversed phase liquid chromatography, and liquid chromatography. However, these techniques often require sample pre-treatment and relatively long analysis time, which can increase costs and thereby make many of these methods not suitable for routine use. Other more advanced methods for detecting biogenic amines include the use of molecular imprinted polymers (MIPs), enzymes, antibodies, single molecule, and array based sensors.
Although current amine sensors (e.g., biogenic amine sensors) show promise, there is still a need to identify and develop new and improved sensors. Particularly, a need exists for technology capable of discriminating analytes within the same or similar class of analytes.